The Hummer has been sitting for a few weeks, the battery is dead, jumped it and left it for a couple of hours and turned it off and still dead. Have ordered a new battery, is there a video on how to change the battery? Plus when I parked the car in the garage for the night, the next morning there is water in the front passenger side floor board?? I read something may be plugged/blocked but where is it and how do you get to it??? Thanks